Showtime's
"Dexter" "wouldn't be where it is without"
Jennifer Carpenter, says her principal co-star and former husband,
Michael C. Hall.

As the serial-killer drama approaches the start of its eighth and final season Sunday, June 30, Hall credits Carpenter -- who's in the running for a Critics' Choice Television Award for her work last year, with the honors being presented Monday (June 10) -- for her "ability to make Debra plausible, and to navigate the phenomenal twists and turns that she's gone through."

Indeed, after discovering the double life of her forensics-expert half-brother Dexter, Miami police detective Debra ended Season 7 by literally killing for him -- fatallly shooting their boss LaGuerta (
Lauren Velez) to protect his secret. And if the
Season 8 trailer is an accurate indicator, Debra is having an extremely difficult time reconciling herself to that action.

"Jennifer is probably the best scene partner I've ever had," says Hall, who is also an executive producer of the series. "We've gone through a lot together as these characters, and there's still a ways to go. I don't really think 'Dexter' could be what it is without what she brings as an actress. I mean, she astonishes me all the time."

Hall has directed Carpenter and the rest of the "Dexter" cast for the first time, taking the reins on the new season's second episode, and he says he's known the plan for the show's home stretch for some time.

"The final two seasons are self-contained, inasmuch as 'Dexter' seasons are," he notes, "but they're maybe two sides of the same coin. And that was created by Deb's discovery."